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Tack welding?
02GF74 - 27/4/09 at 07:36 AM

strangely enough I've never had to tack weld bits prior to proper welding as have been using clamps.

anyways, with my engine mount, it will be easier for me t o tack the bits together then take to bench vice and weld.

so .... how bit are the tacks? about 0.45 s second of blob? or does one do a sthort 10 mm stitch?

later does one just weld over the top of them or stop at the tack and continue after the tack?

will goingover a tack leave an unsightly blob or does the tack melt into the weld pool?

don't suppose anyone has an example photo?

(BTW I am tacking 2 pieces of 3 mm mild steel)


dinosaurjuice - 27/4/09 at 07:44 AM

about a 1s blob is what i do. moving the torch from one surface to next to get good penetration.

keep them fairly small and they can be welded over like they were never there.


David Jenkins - 27/4/09 at 07:55 AM

My tack welds were always a bit blobby (although they did the job) so I just took the top off them with Mr Angry Grinder.


Davey D - 27/4/09 at 08:39 AM

The size of a tack is very much dependent on what gauge steel you are welding to, and how you have setup your welder.

i try to keep mine as flat as possible, that way you can cleanly run straight over them.
you could always run the grinder over them if you feel they are too big


dhutch - 27/4/09 at 10:06 AM

Yeah, you dont need much.
- It is litterally just enough to hold it, so you can let go and weld properbly.
- Its also often possable to get gently move the tacked part if you fractionally off (somtimes the tack breaks, but nothings lost if it is).


Daniel